gas: apply md_register_arithmetic also to unary '+'
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Commit Message
Even a unary '+' has to be considered arithmetic; at least on x86 in
Intel Syntax mode otherwise bogus insn operands may be accepted.
Convert this specific case to binary + (i.e. 0 + <register>). (An
implication is that md_operator(,1,) would need to deal with arch-
specific equivalents of unary '+' is a similar way, if such an arch-
specific variant would be specified in the first place.)
To avoid duplicating what make_expr_symbol() does to construct a
constant-zero expression, simply make its previously local variable a
file-scope static one. This way there's also no need to invoke
clean_up_expression().
---
I have to admit that I find it surprising that only very few targets
turn off md_register_arithmetic. In fact I would have thought it might
better default to off, and targets specifically wanting it (PowerPC is
the one I think definitely wants it enabled) would the turn it on.
@@ -48,15 +48,16 @@ struct expr_symbol_line {
};
static struct expr_symbol_line *expr_symbol_lines;
+
+static const expressionS zero = { .X_op = O_constant };
/* Build a dummy symbol to hold a complex expression. This is how we
build expressions up out of other expressions. The symbol is put
into the fake section expr_section. */
symbolS *
-make_expr_symbol (expressionS *expressionP)
+make_expr_symbol (const expressionS *expressionP)
{
- expressionS zero;
symbolS *symbolP;
struct expr_symbol_line *n;
@@ -73,11 +74,6 @@ make_expr_symbol (expressionS *expressio
as_bad (_("bignum invalid"));
else
as_bad (_("floating point number invalid"));
- zero.X_op = O_constant;
- zero.X_add_number = 0;
- zero.X_unsigned = 0;
- zero.X_extrabit = 0;
- clean_up_expression (&zero);
expressionP = &zero;
}
@@ -750,6 +746,10 @@ current_location (expressionS *expressio
}
}
+#ifndef md_register_arithmetic
+# define md_register_arithmetic 1
+#endif
+
/* In: Input_line_pointer points to 1st char of operand, which may
be a space.
@@ -1127,6 +1127,14 @@ operand (expressionS *expressionP, enum
expressionP->X_op = O_logical_not;
expressionP->X_add_number = 0;
}
+ else if (!md_register_arithmetic && expressionP->X_op == O_register)
+ {
+ /* Convert to binary '+'. */
+ expressionP->X_op_symbol = make_expr_symbol (expressionP);
+ expressionP->X_add_symbol = make_expr_symbol (&zero);
+ expressionP->X_add_number = 0;
+ expressionP->X_op = O_add;
+ }
}
else
as_warn (_("Unary operator %c ignored because bad operand follows"),
@@ -1891,9 +1899,6 @@ expr (int rankarg, /* Larger # is highe
}
else
#endif
-#ifndef md_register_arithmetic
-# define md_register_arithmetic 1
-#endif
if (op_left == O_add && right.X_op == O_constant
&& (md_register_arithmetic || resultP->X_op != O_register))
{
@@ -182,7 +182,7 @@ extern void add_to_result (expressionS *
extern void subtract_from_result (expressionS *, offsetT, int);
extern segT expr (int, expressionS *, enum expr_mode);
extern unsigned int get_single_number (void);
-extern symbolS *make_expr_symbol (expressionS * expressionP);
+extern symbolS *make_expr_symbol (const expressionS * expressionP);
extern int expr_symbol_where (symbolS *, const char **, unsigned int *);
extern void current_location (expressionS *);
extern symbolS *expr_build_uconstant (offsetT);